We have a 1940's house with a square loft aperture where the loft hatch rested internally on the frame aperture. Looking in the likes of B&Q, Toolstation etc, all the available off the shelf hinged loft hatches are rectangular in shape which were not suitable for us. We found Jupiter Blue on the internet who offer made to measure loft hatches. Their website is easy to navigate and explains how to measure for the new loft hatch and has a great choice of options available regarding hinge positions, flange size etc. We purchased the SDS insulated with standard lock, 50mm flange and silver cover for the insulation. The hatch arrived well packaged and within the estimated delivery time given when ordered. The hatch is easy to fit and is supplied with mounting screws and a pole with a key to unlock the hatch and a hook to pull down a ladder if you have one fitted. I highly recommended this company to anyone looking to replace an existing loft hatch.